Performance of dopamine modified 0.5(Ba0.7Ca0.3)TiO3-0.5Ba(Zr0.2Ti0.8)O3 filler in PVDF nanocomposite as flexible energy storage and harvester

Modulation of Electrical Characteristics of Polymer–Ceramic–Graphene Hybrid Composite for Piezoelectric Energy Harvesting

“…Frequency-dependent σ ac plots of two-phase PVDF–BF33BT and three-phase PVDF–BF33BT–GO composites are depicted in Figure a,b, respectively. With the introduction of BF33BT into the PVDF matrix, σ ac decreases due to the insulating nature of BF33BT; however, the increase in the BF33BT concentration from 10 to 40% increases the σ ac due to an increase in ε ′ Figure c shows the σ ac variation with BF33BT and GO concentrations at 1 kHz.…”

“…With the increase in frequency, the contribution of the interfacial, orientation, and dipolar polarization decreases due to the lagging effect of the dipoles, and ε′ decreases. 52 The overall ε′ increases with an increase in the BF33BT concentration in the measured frequency range due to the large ε′ of BF33BT (∼730 at 1 kHz) compared to PVDF (13 at 1 kHz). The frequency-dependent ε′ and tan δ of BF33BT are depicted in Figure S4 of the SI.…”

“…The charging of the 2.2 μF capacitors by the rectified output of the G-0.08 harvester is depicted in Figure d, in which the capacitor achieves the saturation charged state at ∼1.8 V in 550 s with hand tapping. With further continuous hand tapping, the capacitor maintains the charged potential of ∼1.8 V and gets discharged when hand tapping is stopped . The charged capacitor was used to power a calculator with continuous hand tapping, which is shown in Video S2 of the SI.…”

Utilization of Catechol End-Functionalized PMMA as a Macromolecular Coupling Agent for Ceramic/Fluoropolymer Piezoelectric Composites

“…To obtain such a phase, PVDF requires specific treatments like stretching, , quenching from the melt, or solvent casting using N , N -dimethylformamide (DMF). , To circumvent this processing requirement, VDF is often copolymerized with other fluoromonomers such as trifluoroethylene (TrFE) to generate P­(VDF- co -TrFE) copolymers, which crystallize directly in their electroactive crystal phase. , Piezoelectric copolymers possess valuable mechanical properties compared to ceramics, but their ferroelectric (FE) and piezoelectric properties are inferior. Therefore, the preparation of ceramic/piezoelectric polymer composites combining the properties of both materials presents a growing interest. − However, the interface between the piezoelectric ceramics and the fluoropolymer matrix is not strong enough, probably due to the different nature of materials, and is prone to the formation of cavities that can decrease the piezoelectric properties of the composites. , The addition of coupling agents such as dopamine, polydopamine, or their derivatives such as nitrodopamine has been successfully used to reduce the interface issues, as dopamine exhibits a catechol moiety, a well-known adhesive group that can easily and strongly bond to ceramics. − However, since the interactions between a single molecular coupling agent and the polymer matrix could be limited, the synthesis of a macromolecular coupling agent miscible with the polymer matrix and with a catechol group at its chain end presents a growing interest . Indeed, fluoropolymers are well-known to be miscible with poly­(methyl methacrylate) (PMMA), − an inexpensive amorphous commodity polymer that can be produced with a wide range of techniques.…”

Enhanced Piezoelectric Performance of Composite Fibers Based on Lead-Free BCTZ Ceramics and P(VDF-TrFE) Piezopolymer for Self-Powered Wearable Sensors

“…To verify the above demands of the scientific community, several researchers have used lead-free piezoelectric ceramics, such as BaTiO 3 , (K,Na)­NbO 3 (KNN), and (Ba,Ca)­(Ti,Zr)­O 3 (BCTZ), to demonstrate their applicability in self-powered electronics and biomedical sensors. − Among them, BCTZ is considered an attractive material for achieving lead-free and highly efficient energy conversion systems because of its bio-eco-friendly composition and superior piezoelectric coefficient. ,− However, the inherently brittle nature of BCTZ ceramic materials restricts their application in wearable and flexible devices because of their inferior stability under repetitive external stimuli. To achieve superior mechanical robustness of f-PEHs with improved piezoelectric output performances, a lead-free piezoelectric nanocomposite (PNC) film was developed by dispersing BCTZ nanofillers inside a piezoelectric fluoropolymer matrix. − Piezoelectric fluoropolymers such as poly­(vinylidene fluoride) (PVDF) and related copolymers are ideal for the PNC matrix because they require simple and cost-effective fabrication procedures and exhibit higher piezoelectric coefficients than do other piezoelectric polymers. − While the aforementioned lead-free PNC film-based f-PEHs exhibit a high piezoelectric output performance, they still have limitations, such as unscalable film processes and low flexibility, which restrict the applicability of f-PEHs as a permanent energy source for wearable electronics.…”